Pest expert urges countries to act over African Tulip Tree pest

Transcript

A pest expert is urging Pacific countries to move quickly to control the rapidly spreading African Tulip Tree.

The tree is fast becoming a pest in the region, posing a threat to native forests and farm land.

The Pacific Invasives Initiative's co-ordinator, Bill Nagle, told Amelia Langford the tree may have a beautiful flower but it is also a costly pest that needs to be aggressively managed.

BILL NAGLE: It was brought over primarily as an ornamental tree. It was often in botanical gardens throughout the Pacific and then people planted it in their gardens. But unfortunately it has a fruit that produces thousands of seeds and they're dispersed by wind, so they spread rapidly and over a very, very large area. It also produces suckers from the root system. So once a parent tree establishes then you can get secondary grows occurring all the way round. Those two characteristics, the seed dispersal and the ability to sucker, make it very, very difficult to manage so it can take over a large area very, very quickly. It is a major concern in farming land or garden land throughout the islands but it is now being found more and more often actually in the native forest areas as well.

AMELIA LANGFORD: Yes, tell me about the farms. What sort of threat does it pose there?

BN: The main concern is, I guess there's two main areas. One is that it physically takes up the space that people could use for farming, whether it's subsistence agriculture or a more commercial farm. It takes up the entire farming area so it forces people to clear even more land to grow their food supplies. And the second thing is that the cost of dealing with it is very, very high. Because you've got to be constantly going back - you can't just cut it down because it shoots again and you get a very, very rapidly growing tree. So the only way out is to get heavy machinery in and bulldoze it out. But if you leave even one little root fragment behind it will grow again, so you're back to where you started from. Or alternatively you can use herbicide, but no body's really comfortable with using herbicides and there are a lot of dangers associated with them if they're not used safely.

AL: So what do you think needs to be done here?

BN: Ah, that's a real good question. The first thing that needs to be done is somebody needs to find out a biocontrol agent. It seems now that biological control is the only way to reduce it. That's not going to get rid of it of course, but it will reduce the number of trees that are available and it should make it more economical for farmers to get rid of the trees on their land. The second thing is any new infestations that are discovered should be dealt with immediately. People shouldn't just wait and say let's watch it and see what happens over five years. If you see one tree, get rid of it straight away.